Technical Field
The present disclosure relates to a casing of a power transmission device which accommodates built-in components therein.
Related Art
Conventionally, as a power transmission device mounted in a vehicle or the like, there is a power transmission device including a transmission which shifts a speed of a driving force of an internal combustion engine and then outputs the driving force, a differential device which distributes the driving force output from the transmission to left and right driving wheels, and a transfer device which distributes the driving force transmitted to the differential device to other driving wheels located in forward and backward directions.
In the power transmission device, built-in components forming each of the transmission, the differential device and the transfer device are accommodated in a casing. The casing is configured with a plurality of case members joined together through opening edges. A gasket is interposed at a joined portion between the case members to prevent lubricating oil therein from leaking (for example, refer to Japanese Patent Application Laid-Open (JP-A) No. 2010-242829).
However, in the conventional power transmission device as described in JP-A No. 2010-242829, when the case members are joined together (that is, when one of the case members relatively moves to the other), it is feared that the gasket may be displaced and it may take time and effort to assemble the casing. Therefore, it is conceivable to hold the gasket in advance on the case member to prevent a displacement of the gasket at the time of assembly and to easily assemble the gasket.
However, to hold the gasket on the case member, a working process for holding the gasket is required, and it is also necessary to provide a dedicated holding mechanism (for example, a hole for fastening a bolt) for holding the gasket. As a result, a complicated assembling process may occur to hold the gasket or a size of the entire power transmission device may be increased to provide the holding mechanism.